The present invention relates generally to handles for valves and cocks and more specifically to an improved locking handle for valve and cocks employed in air brake systems of railway trains.
Angle cocks or valves are provided throughout the air brake system of railroad trains to interconnect the cars. The open or closed condition of the valve is important to the operation of the air brakes of a train. While the last angle cock on the last car must be closed, all other angle cocks throughout the train must remain open for effective operation of the air brakes. Presently, cars using the regime of the American Association of Railroads ("AAR"), use a two-piece angle cock handle wherein one piece is mounted to the shaft of the actuator of the valve and a second piece pivots relative thereto to lock and unlock the handle and the position of the valve. Stops provided on the cover of the valve engaged with the handle to limit the degree of opening and closing of the handle and valve as well as to lock the valve in a specific condition. A spring or gravity returns the handle to its lowered position. Typical examples are illustrated in FIGS. 1 and 2 to be discussed in detail below.
In Europe and other countries, single piece handles have been used wherein the U-shaped structure of the handle provides its own spring bias and a detent at the end of the handle engages a portion of the cover of the valve housing. A typical example is illustrated in FIGS. 3 and 4 which will be discussed in more detail below. This handle requires a complementary cover and cannot be retrofitted to AAR valves.
The present invention is a unitary handle structure to be secured to the shaft of the valve and cooperate with the stops on the body to delimit and lock the valve element in its open and closed positions. The handle structure includes a socket portion fixed to the stem of the valve element and a handle portion extending from the socket portion and doubling back towards the socket portion and terminating at an end adjacent the socket portion. A detent portion on the end includes a pair of walls sufficiently spaced to receive the stops to lock the valve element in the open and closed positions. The handle portion is flexibly resilient to allow the detent portion to raise and lower with respect to the stops.
One of the walls of the detent has a height high enough and the end of the handle portion is separated from the adjacent portion of the handle by a sufficiently short distance to prevent the one wall of the detent portion from raising above the stops. This could be achieved by the detent portion including a first projection extending downward towards the body a first distance and the handle portion includes a second projection adjacent the end extending up a second distance towards the handle portion. The first and second distance are sufficient to prevent the first projection from raising above the stops.
The detent portion includes a center wall between the first and second walls. The center wall is sufficiently spaced from the first and second walls to receive the stops to lock the valve element in the open and closed position. The center wall extends down towards the body at a greater distance than the first and second walls extend towards the body. The pair of walls of the detent may constitute opposed walls of a slot in the end of the handle portion in which case, the detent includes the projection extending from the slot down towards the body.
As an alternative, the handle may not be a unitary structure, but an integral structure having the socket portion fix the stem of the valve element and a handle portion extending from the socket portion, doubling back towards the socket portion and terminating at an end adjacent the socket portion. The detent portion is on the end and includes a pair of walls sufficiently spaced to receive the stop on the body to lock the valve element in the open and closed positions. The end of the handle portion being movable relative to the socket portion to allow the detent to raise and lower with respect to the stops. This movement may be either from the resilient flexibility of the handle portion or the handle portion may be pivotally connected to the socket portion. The handle may be a stamping, casting, forgery or plastic molded.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.